US1781046A - Antenna - Google Patents

Description

Nov. 11, 1930. BETHENQD 1,781,046

ANTENNA Filed July 1 1925 Fig. i

INVENTOR SEPH B T 0D TORNEY Patented Nov. 11, 1930 UNITED TE iPATENT" c iil:

v aosErH YIBETHQENOD, oFfrA eI's, rRAivoE ANTENNA Applicationfiled July 1, 1925, Serial no; 40,74, and in Frame July 11, 1924.

An object of theinvention is to provide an antenna particularly adapted to the transmission or reception of short wave lengths.

Another object of the invention is to provide an antenna particularly adapted to the transmission or reception of short wave lengths which has all the antenna structure supported at an appreciable height above the ground. I

Still another object of the invention is to provide an antenna for short wave lengths having a counterpoise supported at an appreciable distance above the ground.

' Still another object of the invention isto provide a short wave length antenna which will be directional in its effects and which will be supported at an appreciable distance above the ground. g

It is well known that a very good antenna adapted to the sending out of waves of mean and great length: can be built by means of a horizontal sheet ofwires suspended from towers of as great a height as possible and constituting the aerial properly so called, a'

lead being convenientlybrought down to one pole of a high frequency source mounted on the ground. The other pole of the sourceis in'communication with a second horizontal sheet of wires situated below the former, and

at a slight distance above the ground, this latter part of the system forming what is known as the counterpoise or screen." As a general rule, the fundamental natural wave of this system as hereinbefore outlined falls below the wave length. of the transmission wave.

Now, for the sending of short waves a. similar arrangement may be preserved, and the antenna thus built .may be Worked on a 40 higher harmonic. However, if the operation with the fundamental wave shall be preserved, it is also desirable to preserve the high towers conformably with the devices and means disclosed in the present invention. As a matter of fact, in accordance with cal culation and experience, the role of the counterpoise or screen becomes of so much greater advantage in the presence of short wave lengths, the greater the distance of the said counterpoise above the ground.

Theinvention is illustratedby wayof eX- ample in the accompanying drawing in which: a.

Fig. 1 shows anantenna conformingto the inventiomand," w I 2 shows a directionala'ntennacon forming tothe invention; 1

Referring .to Fig. 1, the towers-1,1, supf 'p ort thQ'hOTlZOIllJfil layer or sheet-of wires 2, at. as great adistan 'ceaboveground'as feaslble; below sald wlres'there is arranged at 3.a counterpoise,insulators 4:..b611lg111 areav than thearea covered by the superposed sheet of wires. .On the otherhand,the down lead 5 of:the said sheet of wires canbe disserted; upon the various suspensionlcables.

be notedtha-t the screen 3may cover a-lariger f posed in various' ways; more" particularly speaking, 1t may comprise elther a single wire, or else acertain number of parallel -wires. -Moreover, the part/of the down-lead ,5which is locatedbeflow the 'counterpoise'fi can be constituted in a different way from the, other part; -More particularly speaking, .togetherwith. the conductor 6 connecting the :counter'poise; with. the hf source,-fit could constitute areal double energy-transmission line possessing convenient. characteristics,

Fig.

another solution comprising likewise the use 1 of towers 1 of relatively *greatheight. The

Q lilzewise shoivsway of example, s5

oscillator properly so called is here constituted by a wire (or system of wires) 9 eXcited in. any desired manner by a'high frequency source (not shown) and with the endin view of realizing a directive action, there is arranged in well-known manner along a parabolic base a series of vertical wires 10 forming i a reflector. These wires constitute as many oscillators excited inductively, and they are preferably tuned to the local oscillator 9. The latter, as is well known also, could be dispensed with provided that the oscillators 10 are respectively fed by currents having relatively convenient phase relations, etc.

v Itgoes Without sayingthat a greatnumber jof modificationsnre co-nceivable. j For in stance, the two layers of Wire Q'andfi of Fig. 1 v. ceuldbe disposed verticelly qr 'eleei'inclined "n'ot .en1y Withreference to the ground; but I, "also with-.referencerto one another so as to v1 realizedirectionel-efiectseither a hepizlon-fl v tail plaine-vonielse in the vertical planeyerel'se egain inboth Furthermore,,the aerial may ,7 V e a d 0 in all ca'ses be excited by a hglll ljQIliC necee I 1 stay, in well-knownmanne't. j

Finally, the Source of high frequency cur 7 rent may itself be mounted at a great height abovethe reimdiieninstence,upoe e nte c mediate platform ofajtower. This arrange. v

mentmay be of; advantage in'the case'of a w Vtriodegenerator plant;the feeding source for I v r j 'these triodes being then placed On the ram 7 V "and'beingi connectedxwith the high'frec 'lency r apparatus through'convenient c'eblesz i' d Having'describedmyinventionjl claim: .7 r y e 1. 'Anrantenna system "for the em'issionso'f 1 shgx t wzvves comprising a Sheet-antennmup; portedyiont owers fixed- :to [the ground, atgca v relatively great; distance f above ground; and

cennterpoise; jsupportedsimilar; tof's said V V gantennafbf saidantennalikewisesuppdrted g V "at aielativdygreat' distance above,ground,

. theldistancebetween said antenna andicounterpoise being-equal to orzleesrth'an the dis- Vta'nce between said countegpoise andgreund. EZ IAn antenna system fbrthelemission oi V 7 v shdrt'waves comp-rising wsheebnn-tenna-sup .ported' gt a- ;re1 ati e1y -.greatdistanceab Ve J c g '1 3 ground;*01'1t0wers fixed to'the greund,iand counterpoise;"insulated"from the grb-undfior' said antenna likewise supported at a relative V I 1y great distancewabove .groundon towers 7 "fixedvt'o thegroundfihe distance befiween sqic'l 4efan't-enfia and connterpoise beingequal tonn e v. e lessit hainthe'dietancexbetween{Said counter;- v f poise and ground, aJ-lefadl-in wire {-frqm the V c 7 antenna connected to one pole'ofa high f-fed -quencyeource, India second lead-in w-ire from 4-5 the counterpoise connected to the'qthenpole ofj sa i'd s0i1rce5'b0th of said leed -inwires c611- stit'uting a double energy-transmission line.-

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